Host Defense Activity in Various Hosts
| Autor: | Rinzo Soejima, Shigenobu Umeki |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Pulmonary and Respiratory Medicine
chemistry.chemical_classification medicine.medical_specialty Oxidase test NADPH oxidase Respiratory tract infections biology medicine.drug_class business.industry Superoxide Antibiotics Critical Care and Intensive Care Medicine In vitro chemistry.chemical_compound Enzyme Endocrinology chemistry Internal medicine Immunology medicine biology.protein Respiratory system Cardiology and Cardiovascular Medicine business |
| Zdroj: | Chest. 102:1780-1786 |
| ISSN: | 0012-3692 |
| Popis: | The superoxide generation of neutrophil NADPH oxidase from healthy subjects, patients with respiratory infections, and patients receiving effective therapy with antibiotics or steroids was investigated. In young healthy nonsmokers the mean oxidase activity of neutrophils in women was significantly lower than that in men. In healthy women the mean oxidase activity was significantly lower in young nonsmokers than in young smokers or the elderly. In young nonsmokers, oxidase activity significantly increased during respiratory infections; however, in elderly nonsmokers, no significant increase in oxidase activity was observed during respiratory infections. The mean oxidase activity in patients receiving steroids was very low. In in vitro experiments using cell-free activation systems of NADPH oxidase, steroids were found to injure the membrane-bound components of the oxidase enzyme. These results suggest that decreased superoxide generation in patients receiving steroids may result from steroid-induced damage in the membrane-bound components of the NADPH oxidase system. The inhibitory effect of steroids on superoxide production may reduce bactericidal action of neutrophils, ie, one defense mechanism of the body against many kinds of pathogens. Therefore, long-term therapy with steroids in the elderly should be avoided at all costs. |
| Databáze: | OpenAIRE |
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